PROJECT SUMMARY Self-regulation predicts later adverse health behavior, a crucial ability that enables one to moderate behavior in contextually appropriate ways1, 2 and helps one regulate delay of satisfaction, adherence, sociality, and attentional flexibility. Influences that alter self-regulation development during a child?s sensitive period of neurodevelopment can have lasting influences on lifecourse health, than if the influences are experienced later in life.3 However, almost 50% of toddlers living in low socioeconomic status (SES) environments demonstrate compromised self-regulation development.4 One influence thought to compromise the development of self-regulation is environments of persistent early childhood contextual stress (PECCS): low SES and/or maternal distress environments that are experienced during a residing child?s sensitive time of neurodevelopment. PECCS persistently provokes activation of the toddler?s stress response system5 (i.e. persistent stress, different from manageable stress that augments normal development6) and interferes with the toddler?s self-regulation development,7, 8 with lasting adverse intergenerational health outcomes.9, 10, 11 Targeting interventions toward each toddler at-risk of altered self-regulation development in PECCS environments to prevent later lifecourse health outcomes is not economically practical, as not all toddlers living in PECCS environments experience compromised self-regulation development.4, 12 A better way to target self- regulation interventions in toddlers would be to target toddlers experiencing persistent stress, however we are not yet able to identify which toddlers actually experience persistent stress. Researchers typically measure toddler persistent stress with much bias via several measures of cortisol in their saliva, yet a more accurate biomeasure may be measuring cortisol in hair. However, hair cortisol as a biomeasure has not been frequently measured in young children, despite wide use in adults.13 This proposed research thus seeks to examine how to better identify young children experiencing persistent stress, to better target early interventions and consequently reduce lifecourse risks of adverse health behaviors and chronic illness, in line with lifecourse health development (LCHD) theory3 and NINR?s Strategic Plan in Wellness14. The aims of this training study are to: (1) Determine associations between PECCS, measured at child age 9-19 months (mos), and child self-regulation, measured at child age 20.5-23.5 mos; (2) Determine the relationship between PECCS, persistent child stress (measured at child age 20.5-23.5 mos via hair cortisol), and child self-regulation; and (3) Determine the relationship between PECCS, biologic persistent maternal distress (measured at child age 20.5-23.5 mos via hair cortisol), persistent child stress, and child self-regulation. This proposed research will use data from an established, ongoing longitudinal birth cohort, the Kids in Columbus Study (KICS) and collect hair cortisol as a biomeasure of persistent stress in mother-toddler dyads. KICS is a regionally representative sample of young children and their mothers in central Ohio living in poverty, a PECCS environment. Results of this study will inform development of a risk model to enhance identification of children at-risk for persistent stress, altered self-regulation, and later poor health behaviors; advance science on biologic chronic stress and stress biomeasures in early childhood; identify novel targets and timing for intervention research; and help answer several NINR Innovative Questions in Wellness. The training plan goals are to provide the applicant with diverse educational and professional experiences to become a research-intensive nursing faculty member.